This invention relates generally to interleaving of protective sheets of paper, plastic, or the like with frozen food patties, and more particularly concerns the application of such protective sheets after the food patties have been frozen.
Traditional methods of interleaving protective sheets with frozen food patties entail applying the protective sheets to the food patties before freezing. However, this presents several problems and limitations; it limits the possibilities of further operations on the patty, such as cubing, breading and scoring, it makes the separation of the patty and the protective sheet difficult after freezing due to large surface adherence, and it has an insulating effect on the unfrozen patty, causing the freezing process to be less efficient.
U.S. Pat. No. 3,772,040 describes a method and machine for inserting protective sheets between falling frozen food patties in a patty stacker. However, placement of loose sheets between frozen patties suffers from several disadvantages; for example, when the stacks are altered or moved about during packaging, storage, or shipment, the sheets are prone to sliding and separating from the food patties.